1. Field of the Invention
The present invention generally relates to an original plate data generation method, an original plate generation method, an exposure method, a device manufacturing method and a computer-readable storage medium for generating original plate data.
2. Description of the Related Art
An exposure apparatus is used in a photolithographic process for manufacturing a semiconductor device such as an integrated circuit (IC). An exposure apparatus illuminates an original plate (also referred to as a “mask” or a “reticle”) and exposes a circuit pattern drawn on the original plate onto a substrate (a wafer) via a projection optical system.
It is desired that a semiconductor device manufacturing process is simplified, and the capacity of an exposure apparatus is improved.
In an exposure apparatus, a resolution which indicates how minute a pattern can be formed on the substrate and a throughput which is indicated by a number of substrates that can be completely exposure-processed in a unit of time are used as indexes for the capacity of the exposure apparatus. As a method for improving the throughput of an exposure apparatus, conventional methods increase a driving speed of a stage that supports a substrate or increase an amount of light intensity on a surface of a substrate.
Meanwhile, as a method for improving the resolution of an exposure apparatus, conventional methods increase a numerical aperture (NA) in a projection optical system, reduce an exposure wavelength λ, or decrease a k1 factor. Furthermore, another conventional method improves the resolution of an exposure apparatus by modifying a pattern of an original plate and using various pattern arrangements.
A representative conventional method inserts an auxiliary pattern having a size with which the auxiliary pattern is not resolved, into an original plate on which a contact hole pattern to be transferred is drawn. This method is one of the conventional methods for decreasing the k1 factor.
Japanese Patent Application Laid-Open No. 2004-221594 discusses a method for deriving how an auxiliary pattern is inserted by a numerical calculation.
The method discussed in Japanese Patent Application Laid-Open No. 2004-221594 obtains a distribution of an approximate image plane intensity (amplitude) by a numerical calculation to derive an interference map indicating the distribution of the approximate image plane intensity (amplitude). The method discussed in Japanese Patent Application Laid-Open No. 2004-221594 arranges an auxiliary pattern around a pattern to be transferred using the interference map.
While Japanese Patent Application Laid-Open No. 2004-221594 discusses an auxiliary pattern arrangement method for improving a depth of focus and an auxiliary pattern arrangement method for improving an exposure likelihood, a method for improving the throughput of an exposure apparatus is not discussed.